Sub-floor conveyor system



Dec. 20, 1960 P. KLAMP ET AL SUB-FLOOR CONVEYOR SYSTEM 4 Sheets-Sheet 2 Filed Oct. 25, 1957 INVENTORS nu K4 Mp @oaf/e7 Men/n 5A Dec. 20, 1960 P. KLAMP ET AL SUB-FLOOR coNvEYoR SYSTEM 4 Sheets-Sheet 'o' P. KLAMP ETAL SUB-FLOOR CONVEYOR SYSTEM Dec. 2o, 1960 4 Sheets-Sheet 4 Filed 001;. 25, 1957 United States Patent "C F SUB-FLOOR CONVEYOR SYSTEM Paul Klamp, St. Clair Shores, and Robert Krammer, De-

troit, Mich., assignnrs to Mechanical Handling Systems, Inc., Detroit, Mich., a corporation of Michigan Filed Oct. 25, 1957, Ser. No. 692,374

16 Claims. (Cl. 104-88) The present invention relates to improvements in a subfloor conveyor system for factories, warehouses, and the like, of the general type illustrated and described in the copending application ofk Paul Klamp, Serial No. 682,797, tiled September 9, 1957.

In-asmuch as the invention more particularly pertains to automatic provisions whereby trucks, dollies, and the like, are switched as desired in their transfer from the control of one sub-floor conveyor chain to a track reach at an angle to the path of that chain, in the interest of simplicity and clarity only a very simple layout embodying such switch means has been selected for illustration.

However, it is to be understood that the improvements of the invention may be employed in various types of conveyor layouts of more or less complex nature, and in these various systems `the matter of whether a truck or like load bearing unit is transferred from a main power conveyor of a loop system onto a connecting or return branch thereof, free or power driven in character, or onto a side branch which may be a dead line, or other connecting or disposal point as called for by the purpose of the system, is immaterial insofar as the special improvements in the switching arrangement are concerned.

Moreover, as will appear to those skilled in the art, the switching mechanism may have utility in a conveyor system in which the actuation of trucks or like load bearing units is effected from beneath the oor, as herein shown, or from above.

It is an obiect of the invention to provide truck conveyor switching mechanism as referred to above, involving improved tow pin structure on the individual trucks and improved means whereby the truck tow pins are disconnected from the actuating conveyor in an automatic fashion.

A further object of a more specific nature is to provide a switching mechanism including a sub-oor conveyor chain by which trucks are normally transported along a main or power driven path, a retractable tow pin structure on the individual truck connected to an actuator for disconnecting the pin from the main conveyor momentarily, and a transfer or branch conveyor to make connection with the tow pin after such disengagement and advance the pin and its truck onto a branch or transfer track reach.

Another object is to provide a switching arrangement as described. in which the actuator to retract the tow pin is automatically operated by a sub-floor mounted comb arm, and in which there are provisions to selectivelv adiust the actuator in relation to such comb arm whereby the tow pin is retracted out of driving relation to a power conveyor trolley or not, in accordance with the adjusted setting of the actuator.

Yet another specific obiect is to provide a conveyor switching mechanism of the foregoing type, involving a sub-floor transfer conveyor having tow pin pusher dogs thereon which are normally maintained in position to push the tow pins bv guided engagement with a fixed upright track or rail beneath the tioor of the installation. In a suggested adaptation of the switching mechanism, the

2,965,043 Patented Dec. zo, i950 transfer conveyor dogs are allowed to fall away from the tow pins after switching, so that the trucks may be advanced manually along the transfer or branch reach.

Itis a general object of the invention to provide switch mechanism of the type described, which is mechanically constituted throughout, being free of electrical, pneumatic and hydraulic operation controls, such as are very expensive and require considerable maintenance, and to provide a switch mechanism in which the switching is initiated by the truck which is to be switched, in accordance with the adjusted setting of its actuator as referred to above.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a fragmentary top plan view of a typical and simple installation of the improved switching apparatus in a factory, warehouse, loading dock or like installation;

Fig. 2 is a fragmentary side elevational view in enlarged scale, as viewed from the line 2--2 of Fig. 1, of the improved truck-controlled switching and transfer chain mechanism of the invention;

Fig. 3 is a top plan view of a load bearing truck equipped with individual adjustable switching means;

Fig. 4 is a view in vertical transverse section along line 4 4 of Figs. 1 and 2, further illustrating the adjustable, comb-type switch arrangement;

Fig. 5 is a fragmentary view in longitudinal vertical section along line 5--5 of Figs. 3 and 4;

Fig. 6 is a view in horizontal section along a line corresponding to the line 6--6 of Figs. 2 and '5;

Figs. 7 and 8 are fragmentary views in vertical longitudinal section along lines 7-7 and 8 8, respectively, of Fig. 4, being enlarged in scale;

Fig. 9 is a fragmentary view in transverse vertical section along line 9-9 of Fig. l;

Fig. 10 is a fragmentary plan view, as viewed from line 10--10 of Fig. 2, showing a portion of the transfer and main trolley conveyor means;

Fig. 11 is a side elevational view of the transfer chain in enlarged scale as viewed from line 11-11 of Fig. 10;

Fig. 12 is a view in vertical section along line 12-12 of Fig. 11; and

Fig. 13 is a schematic top plan View showing an arrangement for decoupling the truck from the transfer chain upon entry onto a branch reach or like reach to which the truck is switched.

Fia. 1 of the drawings illustrates a typical, simple layout for a factory, warehouse or like installation in which a main conveyor track reach 10 is provided with an elongated floor slot 11 beneath which continuously travels an elongated endless conveyor chain, generally designated 12. Insofar as the invention is concerned, the flooring of the installation may be considered to be constituted by a oor plate section 13 in which the slot 11 is formed, a further corner oor plate section 14 coacting with the section 13 in defining an arcuate slot 15 which merges rearwardly with the main floor slot 11, another floor plate section 16 partially defining a branch slot 17, and a still further section 18 in part defining the main conveyor licor slot 11. These sections cover a set of transfer conveyor chain sprockets 20, 21 and 22, al1 idlers mounted on vertical axes.

An endless transfer chain 23 is trained about these sprockets in a generally L-shaped outline, rounded along one reach in general conformity with the shape of the transfer oor slot 15. Suitable provision is made to guide the chain 23 about this reach, in the form of an upright backing rail 24 (Figs. 4 and 10) having a further function to be described.

However, it is in order at this point to describe the improvement, referring to Figs. 2 through 6, in reference 3 to the individual load bearing trucks, generally designated 26, and the tow pin assembly thereof, generally designated 27, by which the transferring of the truck travel iscontrlled.

Each'truck 26'includesa well braced horizontal Yplatform 28 of rectangular4 outline, equipped with pairs of front and rear `swiveled oorjcasters 29. The tow pin assembly 27 is mounted to vthe forward cross piece of the truck 26 by-rneansof a pair of end bearing plates or brackets 30, one projecting forwardly from either side of the truck platform -28, and by a center bracket unit. As best illustrated in'Figs. 3, 4 and 5 this unit comprises a vertical plate 31 welded'to the truck cross piece and having an upright channel member 32 secured thereto which is provided with forwardly projecting top and bottom anges'33, 34, respectively, as well as vertical, forwardly Vprojecting side bearing plates 35 spaced laterally from one another. An elongated transverse hinge rod 36 is journaled 'medially and adjacent its ends in the bearing plates 3 5, 30,respectively, cotter pins at the plates 30 restraining its endwise movement.

The reference numeral 38 generally designates the front bumperforbumper barr'of the truck. It extends horizontallyrand transversely of the truck, being provided at its ends with rearward hinge arms 39 secured by weld to the hinge rod 36; and therear extensions. of these arms are-equipped'with counterweights 40. The weights 40 urge-the bumper38 upwardly, i.e., counterclockwise as viewed in Fig. 2, andY with `the bar in its normal elevated position of that ligure-they reston fixed stops 41 on the truck. Adjacent the center thereof, the 'bumper 38 carries a pair of rearwardly extending, relativelyclosely s lpacetihingngarms 42,y also welded to the hinge rod 36.

The rear 'xtremitiesfof these arms 42 laterally straddle the upright towl pin-44 of the truck, which tow pin is vertically guidedgin an aperture 45 in the-top liange 33 of the mounting bracket 32 (seeA Fig- 5,), and an elongatedslot 46 in the lower bracket flange 34. The top of the tow pin 44 is providedV with a hand grip 47, and beneath this gripa locking pin 48 extends transversely through the-towpin, being receivable in key slots 49 of the`guide aperture 4S. If desired, the tow piny 44 may be elevated to bring `the pin -48 throughV the slot V49, then, rotated 9 07- to hold. itv -inv an elevated position.

.AY circular collar 50 is looselyV mounted on thetow pin 44 beneath the lockingpin 48, and the collar 50 is engageable from. beneath by Vbinge* arms 42, as shownV in Fig. 5,"t'o elevate tow.;pin 44fto the position in that gurvef Such elevation may be occasionedby an impact of the front bumper 38 with a precedingI truck, inwhichcase the tow, -pin 44 is elevated out of driving relation to either the branch conveyor 23 or a trolley pusher dogV 52of the main conveyor system, shown in Fig. 5, in a manner to bedescribed.

However, the tow pin 44 is also capable oftbeingM automatically elevated -to the position referred tofin a switchf4 position in relation to the hinge rod 36, as well as to the sub-oor comb head 56. Forwardly of the shoulder 66, the bore of the arm hub is longitudinally slotted at 67, so that if the actuator arm 64 is swung clockwise or forwardly, from the position of Fig. 7 to that of Fig. 8, the comb 62 is brought into alignment with the hub slot 67, permitting the endwise adjustment referred to above. As 'aligned with'the desired combspace of the key comb 62, Vthe arm is allowed to return to the position of Fig. 7.

The free lower end of the actuator arm 64iis provided with atappet roller 69 adapted-to strike a comb 'tooth 61 of the head 56 (as shownrin Asolid line inFig. 4) to miss such a tooth andgpass between adjacent teeth, or to miss the comb head Y56 entirely (dotted line) depending upon the axial adjustment of the arm 64. To facilitate this, the bumper 38 may be appropriately keyed numerically with the comb head 56, as shown in Fig. 4.

If set for-switching action, atruck 26 proceeding on the main conveyor'in the direction indicated by arrow in Fig. 5, will'have its Vactuator' Varm tappet roller 69 en gaged by the comb head S6, causing the arm 64, through its hub 6?,v to swingA the hinge rod 36 clockwise as viewed in that figure (orcounterclockwise in Fig. 7). This elevates the forked hiuge-arms-42against the collar 56 and thus lifts the tow pin 54 upwardly out of engagement with the main conveyor trolley dog 52. The truck 26 is thus drivingly rie-.coupled fromvthe main conveyor.

In order to insure that the pin cleanly disengages the trolleydog S2, the .pinis urged rearwardly, as shown lin Figs. 5 and6 of the drawings, by a small slide block 71 resting on the lower mounting bracket ange'34; the block xedly carries a. pin 72 extending into a guide cup 73 secured-to` the .upright of the bracket 32, and a small, coill Spring 74 actsbetween this cup and an enlarged head 75 ofthepn72. V'lhuslas the tow pin 44 upwardly clears the trolleycdog .52 it is swunga few degrees toward the rear by the slide block 71, and is prevented from re-entering into engagement with the trolley dog. l

After the arm 64 passes over the comb head 61, depressing the samezin Adoing so, the tow` pin 44 descends gravitationally Vand-is restored .into position for engagement by the transfer chain 23, asV will be described. If desired, provsionvmay bemade,.as,byfflexible cable 77, to control the comb device 53 by shifting its arm54 and head A56 to-aV lowered, rinoperative position, in which switching Vof. trucks Yunder Yits Ycontrol no Vlonger takes lace.` PRerferring now-towFigs. 2, 4 and l0 through l2, the main sub-floor conveyor chain. v12 of the system is pro.c vided at suitable longitudinally spaced intervalsV vwith trolleys 7 8 on-v itsV articulated links79,. S0, the dogs v52 Y being xedto the links.V YEach trolley 78 is also proing operation. This involves the operation of the tow pin assembly 27 by an automatic sub-iloor comb` device 53, including an arm 54 horizontally pivoted vat 55v and provided with a comb-type tripping head V56 acting through a floor plate aperture 57. The arm. 54 is urged by a counterweight 58 on a rear extension 59.thereof; normally resting on a fixed stop 60. Y

Referringto` Fig. 4 ofthe drawings, Vthe combhead 56 is providedv'vith longitudinally spaced teeth 61. Referring nowto Figs. 3, 4, 7 and 8 of the'drawings, the hinge rod 36-has a kev way -or slot .along `its top receiving a toothedfcornb 62, and the top hubV 63 of a pivotal switch actuator arm-64 is received onathe rod 36 cuate, radially inwardly projecting key shoulderf66 which;

when engaged betweensuccessive teeth kof hthe`comb'62,

locks'rthe actuator" arm 64.1inV ais'elected, 'axiallyiadjusite'd vided with a forward pivoted restraining dog 8l, as shownin Fig. 2. The conveyor chain e12 is gudedin its endless ypath by Vits trolleys 78- which, as shown in Fig. 4, areequippedwith tracky rollers 82jtraveling a suitable/-subftloo'r trackr83. The rconveyor 12 may-,be

later-ally guided adjacent the -switchfzoneby a series of elockwise rotation"(as'viewed -in Fig. 10)about this axis' by engagement r'withV a lixed4 stop"shoulder-93-onptlie chain link adjacentthe'pivof92. I "Furthermore, each'off the; dogsv 89;.isl'pro`vided 'with'a :trailing guide'arm 94 equipped with follower roller'95 adapted to bear against the fixed upright guide rail 24. This restrains the dog 89 against clockwise rotation, as

viewed in plan, and keeps it in position for driving engagement with the truck tow pin 44 when the latter is reached. `A forward restraining member 97 is associated with each dog 89, for the purpose of preventing forward over-run of the tow pin 44 relative to that dog. Referring to Fig. 13, in conjunction with Fig. l, the

Avtrucks 26 are released from drivingengagement by the dogs 89, after the tow pin 44 has been drawn about the transfer reach or slot and into the branch slot 17, by

'simply releasing the follower roller 9S of the dog from "restraining engagement by the back-up rail 24, prior to the chain 23 rounding the idler sprocket 22. As the 'follower falls away from the rail end 98, the dog 89 'door slot 17, and the back-up rail 24 may also be continued therealong, if a positive drive of the trucks along the branch is desired.

In operation, assuming that a truck 26 is to be switched by transfer conveyor chain 23 so that its tow pin 44 enters into a branch or transfer oor slot 17 (which may be one of a number of such branch slots), an attendant simply places the truck actuator arm 64v for the tow p'n in such position laterally of the hinge rod 36 that the actuator tappet roller 69 will strike a comb tooth 61 of the sub-door comb head 56 which controls switching into the branch s'lot 17. Upon actuation by the comb head,

l-the actuator arm 64 elevates tow pin 44 out of engage- Athe tow pin, being held in position for its hook 89 to positively engage the pin by rolling engagement of the dog follower 95 with back-up rail 24. Thus the hook 90 oulls the free truck 26 onto the branch or transfer reach.

Should it be desired that a truck 26 pass a junction point of the main and branch track reaches. the actuator arm 64 is simply positioned to avoid engagement with a comb head tooth 61 of the junction point in cuestion, and placed in position for engagement, if desired. w'th the comb head 56 of a further branch, at which the truck releasing and transferring operations described above will then take place.

The mechanisms involved are simple and inexpensive, and rugged and reliable in operation. Control of tro'ley travel and switching is effected solely by coaction of the truck itself and certain sub-oor agencies. The simplicitv of the structural provisions renders tbe invention widelv adaptable to install-ations of many different types and of widely dlering individual make-up and degree of complexity.

What we claim as our invention is:

1. ln combination with a sub-floor conveyor system having divergent track slots, conveyor means operat'ng therebeneath, and a sub-floor unit to control traflic in said slots, a mobile load bearing truck provided with a vertically movable tow element adapted to depend through said slots to guide said truck therealong as moved by said conveyor means and controlled by said control unt, said truck having thereon a control actuator operatively connected to said tow element and provided with means selectively engageable with said sub-oor control unit, and being moved by said engagement with said sub-oor control unit to move said tow element vertically out of position for engagement by said conveyor means, whereby to control movement of said truck by said conveyor means, and means to adjust said actuator on said truck Ytransversely of the path of movement of the truck, thereby to govern its engagement with said control unit. 2. A conveyor system comprising means dening conveyor tracks converging at a switching zone at an angle other than a right angle, endless conveyors having means actuating the same for travel parallel to said respective tracks in vertically spaced and aligned relation thereto, each of said conveyors having longitudinally spaced dogs which pass through a place in said switching zone which is common to the paths of the dogs of both conveyors in the travel of said conveyors, mobile load bearing units having tow members projecting vertically across the path of travel of said dogs at said common place to be engaged and driven by the dogs on said respective conveyors if said tow members and dogs are in predetermined vertical positional relation to one another, means mount'- ing said tow members on said load bearing units for relative vertical movement of said dogs and tow members, and means mounted adjacent o-ne of said tracks in a position to be engaged by and to'operate said load bearing units to selectively alter the relative vertical position of a dog of said one conveyor anda tow member of a load bearing unit at said common place for selective disengagement at said place of said member and dog, a dog of the other conveyor traversing said common place in a position to engage and advance said unit in the direction of the track of said last named conveyor, said actuating means for said conveyors including means driving the latter to advance the dogs of said one thereof through said common place in predetermined timed re lation to those of the other. z

31.` A conveyor system in accordance with claim 2, and furtherlcomprising means engaging said tow members at said switching zone to urge said load bearing units transversely of the track of said one conveyorand into the rtrack of said other conveyor. n y

4. A conveyor system in accordance with claim 2, and further comprising means on the dogs of said other conveyor engaging said tow members at said switching zone to urge said load bearing units transversely 'of the track of said one conveyor and into the track' of said other conveyor.

5. A conveyor system in accordance with claim 2, and further comprising means engaging said tow members at said switching zone to urge said load bearingv units transversely of the track of said one conveyor and into the track of said other conveyor, and means adjacent said last named track to interrupt the driving engagement of the dogs of said other conveyor with said tow members.

6. A conveyor system in accordance with claim 2, and further comprising means on the dogs of said other conveyor engaging said tow members at said switching zone to urge said load bearing units tranversely of the track of said one conveyor and into the trackof said other conveyor, and means adjacent said last named track to interrupt the driving engagement of the dogs of said other conveyor with said tow members.

7. A conveyor system in accordance with claim 2, in which said tow members have means operatively connected thereto and actuated by said means engaged by and operating said load bearing units for shifting said tow members vertically out of position to be engaged by a conveyor dog.

8. A conveyor system in accordance with claim 2, in which said load bearing units have a bumper movably mounted thereon and moved by impact with another object, and means operatively connecting said bumper to the tow member to shift the latter vertically out of position to be engaged by a conveyor dog.

9. A conveyor system in accordance with claim 2, in which said tow members have means operatively connected thereto and actuated by said means engaged by and operating said load bearing units for shifting said tow members vertically out of position to be engaged by a, conveyor dog, said load bearing units having a bumper '7 Airmllzl-ymounted thereon and -movedby impact with an'- ot-her, ,object,.iand means :operatively connecting said bumper-tothe :towA member to shiftv the latter vertically ont ofzpo'sitiom to-ibe engaged byaconveyor dog.

y: 10.v Arconveyor"systemA in accordance with claim 2, in 'whichfsaid tow members have means -operatively connected-thereto and actuated by# said -means engaged by .and `operating said load Vbearing units for shifting said .tovv'members vertically out of Apositionto be engaged by la conveyor dog, and further ycomprising means on `the dogs ofzsaid other conveyor engaging 'said tow members at said switching zone to urge'said load :bearing units transverselyrofthe track of said oneaconveyorand into the' track ofsaid other-conveyor.

V121. A conveyor system in accordance with claim 2, in vwhich said load beringfunitsfhave a bumper movably mounted thereon and moved by impact with another obiect, 'and` means operatively connecting said bumper to the towmember to shift the latter vertically out of position to `be yengaged bya conveyor dog, and further comprising means'on the dogs of said other conveyor engaging sai'd'tow members at said switching zone to urge said *another fobiect, rand- -means operatively connecting said bumperxto the^towmember tov shift the lattervertically .ou'tof--position tobe'engaged'by-a-conveyor dog, and

' #further comprising meansonthe dogs of said other comveyor engaging said tow members atfsaidrswitching zone tcr'zurgev said -loadnbearing -units tranversely of the track Voffsaid oneconveyorand Vinto the track` of saidother oonveyc'n'.- I

13.-A conveyorV system in accordance with claim 2, in

-which said tow members have means operatively connected thereto and actuated by said means engaged by and operating said loadY bearing units for shifting said Vvtow' members vertically out of position to be engaged by af conveyor i dog, andifflirther comprising .means engaging. t

-ifo

isaidftow lmembers at :said ,switching zone -tonrgesaid load bearing-v units transversely ofthe track f said 'ne conveyor t and into the track tfisaidA other covyo 14. Aconveyor lsystemin accordance with lm[2,`in Vwaren me dogs 4ofsaia .otherxceve'yr lare' gpivitlty `mounted*thereontfor movementlto axidfm position 'fo :engageand drivefatow member, and means fo fhldig said dogsin saidiengaging and driving position asfthey jpassfthrough said switching'z'one, and for releasingsai'd ,dogs -for movement out offs'aid engaging and driving .position afteripassing thron'gh said switching zone. l5.- A'conveyr'systemin -accordance with claimZ, in which said tow. mei'her'sjof said load bearing'nnitseach have selectively positional rri'eanson said load bearing unitoperativelyconnectedthereto to verticallyshiftjt'hje tow member out-ffpositiont be engaged by ia conveyor dog, and means't lposition,saidlais'tnamed means' 't'o texert .saidV shifting action Vvon' i the4 tow 'r'nember Yor not.

16. ,A conveyor systeiriiri accordance with claim 2, in which said towme'mb'ers 'of said load bearing units each 'haveselectvely positi'onal mean`s on said Vload bearing ,nitope'rfatively connected thereto to vertically shiftrthe `tow membe'rout of position 'to be engaged by a conveyor dog, @and means ,to position said. lajst named means tof -exert'a'id `shifting' .action..on' thezt'ow member or not, and means 4located in advance of said switching zone and engageable withV 'said means 011 gsaid u nt to actuate `the llatte'rjv o`r not, 'in' accordance with the s ele'ctive'ly adjustable position thereof.

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